Orthopedic sole including corrective means for treating metatarsalgia and plantar skin disorders

ABSTRACT

An orthopedic insole capable of being inserted into a shoe or the like for relieving and/or treating skin disorders and/or calluses and/or metatarsal pain comprises at least one semi-rigid corrective element capable of producing an inner metatarsal support, over the rear portion of the head of the first metatarsal, and/or a median metatarsal support, over the rear portion of the second and/or third and/or fourth metatarsal head, and/or an external metatarsal support, over the rear portion of the fifth metatarsal head.

SCOPE OF THE INVENTION

The present invention relates to an orthopedic insole capable of beinginserted into a shoe or the like for relieving and/or treating skindisorders and/or calluses and/or metatarsal pain, designed for anyperson having a skin disorder and more particularly for diabetics inorder to prevent the development of ulceration.

BACKGROUND OF THE INVENTION

In the field of podology, it is well known that plantar calluses or skindisorders can cause difficulties in walking and can develop intoulceration in the case of deficiency in tissue nutrition, as occurs withpatients suffering from so-called type 1 or particularly type 2 diabetesmellitus, or with the elderly having circulatory problems.

A callus is conventionally an excessive formation of normal keratin onthe affected site of the body. Its origin can be linked either todisorders such as psoriasis, mycosis or eczema for example, or be purelymechanical. The formation of calluses is said to be a normal processenabling the foot to be protected from traumas. Plantar calluses spreadover the metatarsal heads and more generally over the second metatarsalhead.

The formation of calluses of mechanical origin basically appears to bedue to excessive pressure that is too great and over too long a periodduring walking. In fact, the increase in pressure stimulates the releaseof cytokines and epidermal growth factors in the epidermis, leading tothe increased production of cells and finally to the appearance ofcalluses. This excessive pressure can be due to anatomical anomaliesthat can cause a modification in gait and dysfunction in the mechanicsof the foot, such as anomalies of the rearfoot and forefoot, digitaldeformations or bony excrescences for example, and/or extrinsic factorssuch as shoes that are ill-fitting, worn for too long, unsuitable, etc.,or sporadic or intensive sporting activities that can cause an excessiveload on certain parts of the body for example.

The treatment of calluses basically consists in the application ofacetylsalicylic acid (aspirin)-, lactic acid- and urea-based cream ontothe callus. Sometimes alpha-hydroxyl acid (obtained from sugar cane) isalso recommended. Furthermore, calluses can be treated by pumice stone,which must first be moistened, or by any other abrasive device.

Soles are also known, called insoles, capable of being inserted into ashoe, comprising recesses and/or cushioning areas extending over thesite of the callus or calluses. This is particularly the case of theGerman Patent Application DE 196 03 755, Japanese Patent Application JP6054702, American Patent Applications U.S. 2001/0039746 and U.S.2005/0166425 and American Patent U.S. Pat. No. 5,768,803.

Nevertheless, all these treatments and all these soles do not correctthe cause of the appearance of calluses so as to prevent them fromregularly reappearing. Moreover, despite the treatments, it is sometimespossible to see suppuration occur, linked to an infection of the serousbursa located beneath the callus that can lead to ulceration,particularly among diabetics.

French Patent Application FR 2 869 507 is also known, which describes araised relief plantar orthosis allegedly enabling the treatment of thevast majority of individual cases. The said plantar orthosis comprises,from the front to the back, over a substantially flat area, so-calledsubcapital areas, namely one area for the first metatarsal head and onearea for the fourth and fifth metatarsal heads and, behind these areas,separated from each other, one retrocapital bar area or retrocapitalsupport and having a relief whose thickness varies. The retrocapital baris an element located just behind the metatarsal heads, which constituteas a whole the metatarsal palette.

This type of sole, apart from the fact that the thickness of between 1and 10 mm of the raised elements is too great causing too muchdiscomfort for patients making this type of sole totally unusable, doesnot allow the cause of the appearance of calluses to be rectifiedbecause the retrocapital bar is located behind the metatarsal heads.

BRIEF DESCRIPTION OF THE INVENTION

One of the aims of this invention is therefore to remedy these drawbacksby proposing an orthopedic insole of simple design and low cost, adaptedto the morphology of the foot of each patient and enabling excesspressure to be eliminated in order to eliminate calluses and relievepatient's pain.

To this effect and according to the invention, an orthopedic insole isproposed capable of being inserted into a shoe or the like for relievingand/or treating calluses and/or metatarsal pain; said sole is remarkablein that it comprises at least one semi-rigid corrective element capableof producing a so-called inner retrocapital support on the rear portionof the head of the first metatarsal, and/or a so-called medianretrocapital support, on the rear portion of the second and/or thirdand/or fourth metatarsal head, and/or a so-called outer retrocapitalsupport, on the rear portion of the fifth metatarsal head.

Said corrective element is preferably positioned on the lower face ofsaid sole.

Moreover, said corrective element is advantageously connected to thesole in a removable manner.

According to a variation of the sole, said corrective element has fixingmeans capable of cooperating with matching fixing means connected to thelower face of the sole.

On its lower face, the sole comprises at least one recess extending fromthe inner edge to the outer edge of the sole, opposite the metatarsalheads, and in which the corrective element is capable of beingpositioned.

According to another variation, on one of its faces the said correctiveelement has loops and/or hooks capable of cooperating with hooks and/orloops.

Advantageously, on its lower face the sole has a recess located in frontof the metatarsal heads, at the plantar pad, said recess extending fromthe inner edge to the outer edge of the sole, and capable of receiving aso-called lower anterocapital element having pre-cut lines in order toenable the creation of at least one hollow under the callus or callusesand/or skin disorders. This enhances the cushioning located in front ofthe metatarsal heads and, in association with an optional flexibleplantar pad, beneath the metatarsal heads on the upper face of the sole.The said lower anterocapital element is pre-cut into five areas so as tocreate in certain cases a hollow at one or more metatarsal heads inorder to reduce the pressure on said head or heads.

Incidentally, the sole comprises on the one hand an anti-valgus oranti-pronation corrective element capable of being inserted in aso-called anti-valgus recess made on the lower face of the sole, alongits inner edge, under the plantar vault, and on the other hand ananti-varus or anti-supination corrective element capable of beinginserted in a so-called anti-varus recess made on the lower face of thesole, along its outer edge, at the plantar vault.

Advantageously, on its upper face the sole has means guiding theprogression of the foot along the physiological axis of the gait.

These means consist in a sub-scaphoidian profiled element, on the upperface of the sole, which substantially has the shape of a hemi-domeand/or in a sub-cuboidian element located, on the upper face of thesole, on the outer side of the sub-scaphoidian element and having theshape of a bean, with its convexity facing backwards from the medianlongitudinal axis of the sole and/or in a medio-tarsian axial means, onthe upper face of the sole, oval in shape and widening towards the frontto terminate just before the metatarsal heads in order to distribute thesupport beneath the metatarsal palettes.

Preferably the sole has means to stress, from the strike of the stepusually performed by the heel, the articular receptors located betweenthe talus and the calcaneus.

The said means consist in a subcalcaneal longitudinal profiled channel,or console, of increasing thickness from the heel to an area locatedsubstantially directly below the neck of the talus.

Said console is positioned either on the upper face of the sole or onthe lower face of the sole performing an additional stiffening function.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and features will emerge more clearly from thefollowing description of several variations, given by way ofnon-limiting examples, of the orthopedic sole according to theinvention, with reference to the accompanying drawings, in which:

FIG. 1 is a bottom view of the orthopedic sole according to theinvention,

FIG. 2 is a side view of the orthopedic sole according to the invention,

FIG. 3 is a schematic view of a longitudinal section of the orthopedicsole with a foot resting on it,

FIG. 4A to 8A are top views of the removable corrective elements of theorthopedic sole according to the invention,

FIGS. 4B to 8B are side views of the removable corrective elements ofthe orthopedic sole represented in FIGS. 4A to 8A,

FIG. 9 is a top view of a variation of the orthopedic sole according tothe invention,

FIG. 10 is a side view of the variation of the orthopedic sole accordingto the invention represented in FIG. 9,

FIG. 11 is a bottom view of a second variation of the orthopedic soleaccording to the invention,

FIG. 12 is a side view of the second variation of the orthopedic soleaccording to the invention represented in FIG. 11,

FIG. 13 is a schematic view of a longitudinal section of a device formeasuring the footprint in order to determine the appropriate size ofthe orthopedic sole according to the invention,

FIG. 14 is a top schematic view of the template of thefootprint-measuring device enabling the size of the sole to bedetermined on the basis of the position of the metatarsal heads inrelation to the calcaneus, i.e. in relation to the patient's heel.

DETAILED DESCRIPTION OF THE INVENTION

For obvious reasons of simplifying the description, only one soleaccording to the invention will be described, corresponding to the leftfoot for example, the right sole being deduced by symmetry.

With reference to FIGS. 1 and 2, the sole according to the invention hason its lower face a semi-rigid corrective element capable of providing aso-called inner retrocapital support 1, on the back part of the firstmetatarsal head, and/or a so-called median retrocapital support 2, onthe back part of the second and/or third and/or fourth metatarsal head,and/or a so-called outer retrocapital support 3, on the back part of thefifth metatarsal head. Said inner 1, median 2 and outer 3 retrocapitalcorrective elements are advantageously connected to the sole in aremovable manner. On its lower face, the sole has at least one recess 4extending from the inner edge to the outer edge of the sole, oppositethe metatarsal heads, and in which the inner 1, median 2 and outer 3retrocapital corrective element or elements are capable of beingpositioned. The walls of the recess 4 are inclined towards the inside ofsaid recess 4 from its bottom to the edge of the said recess, i.e. tothe lower face of the sole, in order to form a lip 5 at the edge of therecess 4. This recess 4 is capable of accommodating at least one of theinner 1, median 2 or outer 3 retrocapital corrective elementsrepresented in FIGS. 4A to 6B. Each retrocapital corrective element 1 to3 is substantially triangular in shape and has at its periphery achamfer 6 so that the lip 5 at the periphery of the recess 4 holds saidretrocapital corrective elements 1 to 3 in place in said recess 4.

Clearly, the edge of the inner retrocapital corrective element 1 and ofthe outer retrocapital corrective element 3 which is adjacent to theinner and outer edge of the sole respectively when the said elements 1and 3 are inserted into the recess 4 does not have a chamfer 6.

Furthermore, the inner 1, median 2 and outer 3 retrocapital correctiveelements are made of a more rigid and denser material than the materialof the sole and are inserted into the recess 4 by elastic deformation ofthe lip 5 thereof.

It will be noted that the particular shape of the recess 4 and theretrocapital corrective elements 1 to 3 prevent any inadvertentmovement, as well as any escape, of said corrective elements duringwalking or running

Moreover, it will be observed that the retrocapital corrective elementsare not in contact with the foot, thus avoiding any injury to theplantar skin such as cuts, blisters, clefts or suchlike. Nevertheless,it is very clear that the inner 1, median 2 and outer 3 retrocapitalcorrective elements can be positioned on the upper face of the solewithout departing from the scope of the invention.

Advantageously, with reference to FIGS. 1 and 2, the sole has on itslower face a recess 7 positioned in front of the metatarsal heads, atthe plantar cushion, said recess 7 extending from the inner to the outeredge of the sole, and capable of receiving a so-called loweranterocapital element 8 having pre-cut lines 9 in order to enable thecreation of a hollow beneath the callus or calluses and/or skindisorder. These pre-cut lines 9 delimit removable elements. Theseremovable elements extending opposite the calluses are removed in orderto create a hollow on the lower face of the sole. Moreover, in the sameway as before, the walls of the recess 7 are inclined towards theinterior of the said recess 7 from their bottom up to their respectiveedge in order to form a lip 5 round the edge of the said recess 7. Thesaid lower anterocapital element is flat and has round its periphery,along its proximal and distal edges, a chamfer 6 in order to ensure thatit locks into the recess 7. In this particular embodiment, theanterocapital element 8 has 4 pre-cut lines 9 extending from theproximal edge to the distal edge respectively of the said anterocapitalelement 8.

Thus, with reference to FIG. 3, the retrocapital corrective elements 1to 3 exert an upward pressure P1 onto the back part of the correspondingmetatarsal head(s) enabling the excessive pressures that cause theformation of the callus or calluses to be corrected. And the hollow orhollows 7 formed by removing the movable parts of the anterocapitalelement 8 between the pre-cut lines 9 allow the sole to be compressedinto the hollow when a pressure P₂ (FIG. 3) is exerted during walkinglimiting rubbing against the callus D on the upper face of the solesimultaneously making walking much more comfortable.

As the appearance of calluses is often due to a problem of posturecausing excessive pressure on the metatarsal heads, the sole accordingto the invention advantageously has posture-correction means. Thus thesole, with reference to FIGS. 1 and 2, also has a second so-calledanti-varus or anti-supination recess 10, generally rectangular in shape,located along the outer edge of the sole and extending from the cuboidto the first recess 4 of the retrocapital corrective elements and afinal so-called hemi-dome shaped anti-valgus or anti-pronation recess 11located along the inner edge of the sole under the plantar vault. In thesame way as described above, the wall of the anti-varus 10 andanti-valgus 11 recesses is inclined towards the inside of the saidrecesses 10 and 11 from their bottom to their respective edge in orderto form a lip 5 bordering the said recesses 10 and 11. Each of theanti-varus 10 and anti-valgus 11 recesses is capable of accommodating ananti-varus 12 and anti-valgus 13 corrective element respectively,represented successively in FIGS. 7A, 7B and 8A, 8B; the anti-varuscorrective element 12 is generally rectangular in shape and theanti-valgus corrective element 13 is the shape of a hemi-dome. Each ofthese corrective elements is flat and made from a more rigid and densermaterial that the material of the sole; these elements also have roundtheir periphery a chamfer 6 in order to ensure that they lock into theirrespective recess.

According to a variation of the sole, the said retrocapital correctiveelements 1, 2 and 3, the anterocapital element 8 and the anti-varus 12and anti-valgus 13 corrective elements have fixing means capable ofcooperating with additional fixing means connected to the lower face ofthe sole.

These means can consist for example in lugs projecting from the upperface of the corrective elements 1, 2, 3, 8, 12 and 13 and capable ofcooperating with corresponding holes located at the bottom ofcorresponding recesses 4, 8, 10 and 11, corrective elements 1, 2, 3, 8,12 and 13 therefore not having a chamfer and the recesses 4, 8, 10 and11 not having a lip 5.

Alternatively, these means can consist in loops and/or hooks capable ofcooperating with hooks and/or loops in order to form Velcro-type fixingmeans.

Moreover, it is very clear that the corrective means 1, 2, 3, 8, 12 and13 can be fixed removably onto the lower or upper face of the sole byany appropriate means well known to a person skilled in the art orpermanently on the lower and/or upper face of the sole by means of glue,double-sided adhesive or any other means well known to a person skilledin the art without departing from the scope of the invention.

According to a particularly advantageous variation, with reference toFIGS. 9 and 10, the sole has on its upper face, means to stress, fromthe strike of the step usually performed by the heel, the articularreceptors located between the talus and the calcaneus and means guidingthe progression of the foot along the physiological axis of the gait asdescribed in French Patent Application 2 676 918, filed by theapplicant. These means basically consist in a profiled channel, called aconsole 14, and a set of profiled elements 16, 17, 18 distributed alongthe entire length of the sole to create a rail around which the foot isguided.

The console 14 extends longitudinally from the heel to the front end ofthe calcaneus, just vertically below the neck of the talus. The saidconsole 14 has a thickness that increases from the heel to its front end15. By way of a particular example, the height of the console 14increases gradually from 1 mm to 2 mm from the heel to its front end 15.

The set of profiled elements 16, 17, 18, from the back forwards, i.e.from the heel towards the tip of the foot, consists of a subscaphoidianprofiled element 16, a subcuboidian profiled element 17 and amedia-tarsian axial means 18. The subscaphoidian profiled element 16extends along the console 14 towards the interior of the foot in themanner of a hemi-dome. This subscaphoidian profiled element 16 has inthis example a height of about 2 mm and thus extends the front end 15 ofthe console 14.

The profiled subcuboidian element 17, in the top view, according to FIG.9, has the shape of a bean corresponding generally to the projection ofthe shape of the cuboid on the sole. This element 17 is located on theouter side of the subscaphoidian element 16, its convexity turnedbackwards, at about 45° from the median longitudinal axis of the sole.The thickness of the said element 17 increases from the side towards thecentre and from the back forwards gradually to reach a height of about 4mm.

The media-tarsian means 18 is oval in shape, i.e. roughly the shape of adrop of water, widening towards the front and ending just before themetatarsal heads of the foot.

This media-tarsian element is domed; its height varies longitudinallyfrom a height of 2.5 mm to reach a maximum height in the order of 3.5mm, at about two thirds of its length. It will be observed that, duringthe progression of the step, the console 14 stresses the calcaneus ofthe foot, whether a flat foot or a high-arch foot, in order to preparethe continuation of the step under good conditions; then thesubscaphoidian 16 and/or subcuboidian 17 profiled elements which act aslateral stabilisers for the foot, encourage the foot to stay within thephysiological rail of the gait and the media-tarsian element 18 preparesthe terminal digitigrade phase of the step by distributing the supportof the foot under the metatarsal palettes so that this support remainschanneled along the axis of the second metatarsal head through which thephysiological axis of the gait passes.

Advantageously, the sole has on its upper face an upper anterocapitalelement called the upper plantar pad 19 extending from the inner edge tothe outer edge of the sole in front of the media-tarsian element, havinga general bean shape, and made of a flexible material so as to providecushioning when walking This upper plantar pad 19 is between 2 and 4 mmin height and is made of any flexible material well known to a personskilled in the art.

According to a final particularly advantageous variation, with referenceto FIGS. 11 and 12, the sole has means to stress, from the strike of thestep usually performed by the heel, the articular receptors locatedbetween the talus and the calcaneus and means guiding the progression ofthe foot along the physiological axis of the gait. These means basicallyconsist in a profiled channel, called a console 14, and a set ofsubscaphoidian 16, subcuboidian 17 and medio-tarsian 18 profiledelements distributed along the entire length of the sole to create arail around which the foot is guided. Moreover, the sole has, in thesame way as before, an upper plantar pad 19. This variation differs fromthe previous one by the fact that the console 14 is located on the lowerface. In this way, apart from its function of stressing the articularreceptors during the strike of the step, the console 14 has astraightening function.

In order to enable the rapid supply of soles to patients, the inventionalso includes a conventional foot cast taking device 100, with referenceto FIGS. 13 and 14, enabling a foot cast to be taken by the transfer ofink or by the deformation of foam for example, well known to a personskilled in the art, and a transparent or translucent template 110 havingpre-defined lines 120 corresponding to the position of the metatarsalheads for different sizes. Thus, all that is required is to take thepatient's foot cast then match the rear part of the template to the rearpart of the heel of the cast thus taken and read the corresponding size.As the rear part of the foot cast is 6 mm further forward than the rearpart of the heel, the template has been designed with this difference inmind. All that is then required is to insert the retrocapital correctiveelements 1 and/or 2 and 3 into the recess 4 of the sole corresponding tothe size measured and cut the lower anterocapital element 8 of the soleat the cutting lines 9, if necessary, in order to create a correctivesole to eliminate the patient's callus or calluses. Said callus orcalluses disappear in about a month and the correction made prevents anyappearance of new calluses.

Lastly, it is very clear that the examples just given are merelyparticular illustrations and are in no way limiting as regards thefields of application of the invention.

1. Orthopedic insole adapted to be inserted into a shoe or the like for relieving and/or treating skin disorders and/or calluses and/or metatarsal pain, comprising at least one semi-rigid corrective element producing an inner retrocapital support, over a rear portion of a head of a first metatarsal, and/or a median retrocapital support, over a rear portion of a second and/or third and/or fourth metatarsal head, and/or an outer retrocapital support, over a rear portion of a fifth metatarsal head.
 2. The insole according to claim 1, wherein said corrective element is positioned on a lower face of said insole.
 3. The insole according to claim 1, wherein said corrective element is connected to the insole in a removable manner.
 4. The insole according to claim 3, wherein said corrective element has fixing means cooperating with matching fixing means connected to a lower face of the insole.
 5. The insole according to claim 4, wherein the lower face has at least one recess extending from an inner edge to an outer edge of the insole, opposite the metatarsal heads, and in which the corrective element is positioned.
 6. The insole according to claim 4, wherein said corrective element has on one of its faces loops and/or hooks cooperating with hooks and/or loops.
 7. The insole according to claim 1, wherein, on a lower face, a recess is located in front of the metatarsal heads, at a plantar pad, said recess extending from an inner edge to an outer edge of the insole, and receiving a lower anterocapital element having pre-cut lines in order to enable creation of at least one hollow under the callus or calluses and/or skin disorders.
 8. The insole according to claim 1, further comprising an anti-valgus or anti-pronation corrective element inserted in an anti-valgus recess a lower face of the insole, along its inner edge, under a plantar vault.
 9. The insole according to claim 1, further comprising an anti-varus or anti-supination corrective element inserted in an anti-varus recess on a lower face of the insole, along its outer edge, at a plantar vault.
 10. The insole according to claim 1, further comprising, on an upper face, means guiding progression of the foot along a physiological axis of agait. 